Low-loss GaInNAs saturable absorber mode locking a 1.3-μm solid-state laser

Abstract

We have demonstrated stable self-starting passive cw mode locking of a solid-state laser at about 1.3 μm using a GaInNAs semiconductor saturable absorber mirror (SESAM). GaInNAs SESAMs show negligible nonsaturable losses, low saturation fluences (11 μJ/cm2) and picosecond decay times which make them well-suited for self-starting and stable cw mode locking. Sub-10-ps pulses were produced with a Nd:YLF laser at 1314 nm. The incorporation of about 2% nitrogen into InGaAs redshifts the absorption edge above 1330 nm and reduces the strain in the saturable absorber grown on a GaAs/AlAs Bragg mirror. Final absorption edge adjustments have been made with thermal annealing which blueshifts the absorption edge.